replace

Synopsis

template<
      typename Sequence
    , typename OldType
    , typename NewType
    , typename In = unspecified
    >
struct replace
{
    typedef unspecified type;
};

Description

Returns a copy of the original sequence where every type identical to OldType has been replaced with NewType.

[Note: This wording applies to a no-inserter version(s) of the algorithm. See the Expression semantics subsection for a precise specification of the algorithm's details in all cases — end note]

Header

#include <boost/mpl/replace.hpp>

Model of

Reversible Algorithm

Parameters

Parameter	Requirement	Description
`Sequence`	Forward Sequence	A original sequence.
`OldType`	Any type	A type to be replaced.
`NewType`	Any type	A type to replace with.
`In`	Inserter	An inserter.

Expression semantics

The semantics of an expression are defined only where they differ from, or are not defined in Reversible Algorithm.

For any Forward Sequence s, an Inserter in, and arbitrary types x and y:

typedef replace<s,x,y,in>::type r;

Return type: A type.

Semantics:

Return type:	A type.
Semantics:	Equivalent to typedef replace_if< s,y,is_same<_,x>,in >::type r;

Equivalent to

typedef replace_if< s,y,is_same<_,x>,in >::type r;

Complexity

Linear. Performs exactly size<s>::value comparisons for identity / insertions.

Example

typedef vector<int,float,char,float,float,double> types;
typedef vector<int,double,char,double,double,double> expected;
typedef replace< types,float,double >::type result;

BOOST_MPL_ASSERT(( equal< result,expected > ));